Method-of and apparatus for burning liquid fuel



March 19, 1929.

H. H. NORTON ET AL METHOD OF AND APPARATUS FOR BURNING LIQUID FUEL Filed Dec 30.v

1922 4 Sheets-Sheet Q I N VEN TOR. W Homer H. Norion Elmer E. Hobbs A TTORN March 19, 1929. HHNORTON ETA 1,706,316

METHOD OF AND APPARATUS FOR BURNING LIQUID FUEL Filed Dec. 30. 1922 4 Sheets-Sheet 2 Homer H. Norton BY Elmer E. Hobbs ATTORNEY March 19, 19 9- H. H. NORTON ET AL METHOD OF AND APPARATUS FOR BURNING LIQUID FUEL Filed Dec. 30. 1922 4 Sheets-Sheet ////I//I////I/////////l INN. vvv mai L 0 .r. H N L 1 v Q Homer H. Norton Elmer E. Hobbs Margh 19, 1929. I NORTON ET AL 1,706,316

METHOD OF AND APPARATUS FOR BURNING LIQUID FUEL Filed Dec. 30. 1922 4 Sheets-Sheet 4 IN V EN TOR Homer H. Norton y Elmer E. Hobbs @N A TTOR1 Y.

Patented Mar 199, 1929..

one stare.

. 1,706,316 rnrsur orrics,

HOMER H. NORTON, OF THE UNITED STATE$ NAVY", AND ELMER HOBBS, 0F PHILA- DELPHIA, PENNSYLVANIA.

METHODOF AND APPARATUS FOR BURNING LIQUID FUEL.

Application filed. December 30. 1922. Serial No. 609,956.

Our invention relates to an improved method of and apparatus for burning liquid fuel, such as oil, to attain high rate of and substantially perfect combustion.

One of the objects of our invention is the provision of :means and method by which large quantities of oil, or other liquid fuel, may be efficiently consumed per unit of time, and the resultant flame or hot gases simply and economically controlled by a simplified and compact form and arrangements of apparatus.

' I lit is a further object of our. invention to provide a pressure atomizer of general application, but particularlysuited, because of its small dimensions, notwithstanding its ca-' pacity to'atomize large quantities of liquid fuel per unit of time, for passage through a tube or hollow shaft surrounded by or carrying an element of a fan or blower, or

of its driving motor,'or both.

ln accordance with one of the aspects of our invention the liquid fuel, as oil, is delivered under pressure, of the order of 50 pounds per square inch and upwardly, to a so-called mechanical or pressure atomizer of any suitable type, and the air, in quantities sufficient to sustain and effect substantially perfect combustion, is operated upon adjacent the point of atomization of the fuel to imparta whirl or helical movement thereto and to efi'ect a current thereof past the point of atomization; and further in accordance with our invention the inner portion 'of the moving air column is subjected adjacent to the point of atomization to outwardly di-' rected difiusion, and outer vanes are provided to bring to desired magnitude the de-i' gree or rate of whirl orhelical movement of the outer or surrounding portions of the air column I Heretofore; in some instances, the liquid fuel has been delivered under pressure to a mechanical or pressure atomizer adjacent the mouth of a fire box, and the air for combustion has been supplied by a blower located at a considerable distance from the mouth of the furnace and delivered through a conduit to the burner casing enclosing the atomizer, and in such apparatus it generally has been necessary to inter-pose between the blower and burner casing structure for imparting a swirl or helical movement to the air within the burner casing. Such swirl imparting structure has caused a throttling eifect upon the air, and such effect together with the friction losses induced by passage of the air through the conduit have necessitated generation by the blower of .air pressure much method is objectionable because of the necessity for continuing in operation a blower of sufficient capacity to maintain the boiler room' under the necessary pressure even when all but one of the boilers is out of service. This system is further objectionable by reason of the need to maintain the boiler room air tight and the attendant discomfort to the men employed in the boiler room.

lin accordance with anothersystem, air in 2 volume sufiicient for combustion is supplied to thefurnace by induced draft, such as provided by a high smoke stack or syphoning means in the escape passes of the boiler. Such system generally requires mechanical means at the burner casing to induce a whirl or helical movement of the air before it reaches the atomized oil.

Another method of burning oil is by the use of rotary atomizers comprising a holy low shaft-like member rotated at-high speed and flared to a cup-like form at its discharge cinch-oil being supplied through such hollow member and the member rotated at high speedto throw the oil off the edge of thecup. To assist atomizations it has been necessary to supply air under high pressure,

through a restricted passage surrounding" 'the spray cup. Sufficient additional air to secure combustion of the fuel so atomized hasbeen supplied by natural draft or otherwise', the furnac'e'around the casing. This method of burning oil-is disadvantageous because of the amount of oil that may be so atomized by a burner of given dimensions is relatively small and it has not been possible properly to control the angle of diffusion of the fi me with respect to the burner and the walls of the furnace. The amount of oil that can be consumed in these types of rotary atomizers, using a fan or blower of. .a given size, is much less than the amount of oil that can be burned by an apparatus of the same size wherein the fan is required through openings in the front of only to deliver air in large volume at low pressure instead of small volume at high pressure.

Our invention eliminates the various disadvantages above referred to, and enables us to secure a more effective control of the angle of diffusion of the flame, and of the relativevolumes of air and fuel. We effect the economical combustion of a large amount of fuel per unit of time by apparatus occupying a minimum of space, and which may be employed either as a unit independent of or in combination with oil burning apparatus of other types.

Some of the forms of apparatus which may be employed in practicing our invention are shown in the accompanying drawings wherein:

Fig. 1 is a View, partially in side elevation and partially in section, of a burner embodying our invention.

Fig. 2 is a sectional view of the fuel supply coupling shown in Fig. 1.

Fig. 3 is a view taken on the line 23-3 of Fig.

Fig. 4 is a plan View, partially in section, of the fuel supply coupling of Fig. 1.

Fig. 5 is a front elevational view of the vanes of Fig. 3.

Fig. 6 is a view taken on the line 6-6 of Fig. 5.

Fig. 7 is, a longitudinal sectional view of the atomizer which we employ.

Fig. 8 is a view taken on the line 8-8 of Fig.

Figs. 9and 10 are views corresponding to those of Figs. 1 and 3, but showing a modified formof apparatus.

Figs. 11 and 12 are, respectively, plan and elevational views of one of the fan blades.

Referring more particularly to Fig. 1, the apparatus is shown as applied to the furnace 11 of a boiler (not shown) and includes a burner casing 12 which may be secured to the furnace 11 in any convenient manner. A turbine casing 13 is secured to the casing 12 by bolts 14.

The turbine casing 13 is provided with a chest 15 through which motive fluid, as steam, is supplied to drive a turbine rotor 16 mounted upon a hollow shaft 17 supported in antifrietion bearings carried by the casing 13. A fan 18 is mounted upon the forward end of the turbine shaft 17 and is driven thereby to induce flow of a. column of air through the casing 12 into the fire box 11. The fan is of the. axial flow type, whose blades may be of any suitable form, such for example, as-indicated in Figs. 11 and 12.

An end plate 19 is provided upon the rear end of the turbine casing 13 and serves to support a stationary sleeve 20 spaced from the interiorsurface of the hollow rotating shaft 17. A stationary sleeve 20 is provided at its forward end with a spider 21 serving to support at its forward end a diffuser 35 comprising the concentric diffuser elements or vanes 35, 35, 35, 35 and 35*. sleeve 20 supports a fuel pipe 22 housed therein and carries at its outer end a pres-' sure or mechanical atomizer 23 of any suitable type. The sleeve 20 and the fuel pipe 22 are relatively movable longitudinally, a set screw 24 threaded in the sleeve 20 serving to hold the sleeve 20 and the fuel pipe in any desired relative position of longitudinal adjustment, (Fig. 2). A coupling 25 has screw threaded connection with the rear end of the fuel pipe 22 and provides communication between such pipe and a flexible tube 26 leading to a supply of liquid fuel, as oil, under pressure preferably upwards of 50 pounds per square inch.

As shown more clearly in Fig. 4, a pair of bolts 27 is supported by the end plate 19 of the turbine casing, and a cross head 28 isslidably supported upon said bolts and provided with set screws 29 by means of which it may be secured in any desired position of adjustment longitudinally of said bolts, to effect adjustment of the fuel pipe 22 and the atomizer 23. yoke 30 is supported by screws 31 uponthe cross head 28. The outer end of the yoke 30 carries a screw 32 by means of which members 25 and 25 of the coupling 25 can be drawn together toeffect a pressure tight joint.

The atomizer 23 isof the mechanical or pressure type, and when of the character illustrated comprises an outer member 23 and a chambered block 23". The end of the fuel pipe is threaded to permit of the attachment of the member 23 thereto, in abutting engagement with the extension 23 to prevent leakage of oil through the threaded connection between the member 23 and the pipe 22.

The member 23 is provided with a small opening 34 serving as the orifice of the atomizer. The block 23 is provided with passages 33, an annular groove 33 and slots 33 that afford communication between the groove 33 and a chamber 33 within the block. The chamber 33 is open at its forward end and has communication with the orifice 34. The slots 33 are disposed with their longer walls tangential to the circular wall of the chamber 33. Oil supplied through the fuel pipe 22 under pressure flows through the passages 33, 33 and 33 to the chamber 33 and thence to the orifice 34 from which it emerges in the form of a cone of atomized fuel. The oil upon passinginto" the chamber 33 is given a whirling movement, and, owlng to the pressure, w1th1n such chamber, is directed with a screw like motionthrough the'orifice 34 from which it emerges in the form of a, cone-shaped field of atomized fuel. a

The

In the operation of the device, oil is supplied through the pipes 26 and 22 under sufficient pressure to effect atomization. The turbine 16 rotates the fan 18 to supply air in quantity sufficient to effect substantially perfect combustion within the furnace. The fan draws air through openings in the rear of the casing 12 as indicated by the arrows, and forces it forwardly in an axially flowing column having swirling or helical movement. As the body of air approaches the forward end of the casing 12 the central portion of the column passes be tween the vanes of diffuser 35, while the air of the column surrounding such central portion passes between vanes surrounding the diffuser and secured to the interior of the casing 12 and so disposed that the extent of swirl or helical movement of the air emerging from the passages between vanes 40 is of predetermined magnitude or lies within a suitable range. If the fan be driven at low speed, as when fuel in small quantity is forced through the atomizer, the swirl imparted bythe fan to the air may not be sufficient to effect proper mixture thereof with the atomized fuel and the vanes 40 will in such case increase the swirl to a proper or suitable degree. If the fan is driven at high speed to supply sufficient air for a relatively large amount of fuel, the swirl imparted by the fan to the air may be too great, in that the angle of flame diffusion at the front of the burner may be too wide and the flame directed against the wall of the furnace opening. Under such condition, the vanes 40 decrease the swirling movement of the air and, as above explained, cause it to emerge therefrom at proper or suitable angle. The vanes 40, therefore, serve to correct or modify the extent of swirl of the outlying portions of the air column. The whirling streamfof air set up by the fan is not substantially expanded or contracted during its passage to the combustion chamber, and is still whirling when it encounters for effecting mixture with the already atomand enters the cone-shaped field of fuel.

Beferring'now more particularly to the concentric vanes '35, 35*, 35, etc., they are maintained in assembled relation by ribs 411 to ,which thearms of the spider 21 are secured. The vanes of the diffuser are disposed circumferentially of the atomizer 23 and divide the inner portion of the air column flowing therethrough into concentric currents, without substantially affecting such swirl as they-may have.

Those diffuser vanes nearest the atomizer 23 are inclined forwardly and radially outward at a considerable angle in order to deflect radially the air flowing past them,

to assist in securing a wide angle of diffusion of the atomized fuel and, consequently, of the flame, at the mouth of the furnace. Those of the diffuser vanes which are located by a succession of currents of air, thus preventing accumulation of. carbon deposits below the atomizer such would occur if fuel were permitted to accumulate beneath the atomizer and be consumed by the flame from'the main body of the mixture.

The passages between the vanes of the diffuser are preferably narrowed or reduced to some extent intermediate their ends, as will appear from Fig. 1, thus affording for the currents of air while within the diffuser convergent-divergent passages whose cross sectional areas first decrease and then increase to magnitudes greater than at the entrances to the passages. Likewise, the

ribs 41 are thickened at their rear ends, the

flaring of the front ends of the vanes of the diffuser 3'5 and the ribs 11 causes an outwardly directed diffusion of the air emerging from therebetween, thereby effecting a lpetter mixture thereof with the atomized uel.

As will be hereinafter explained, the pressure set up within the casing 12 by the fan 18 is relatively low, the oil being atomized purely mechanically, as by pressure, and the fan is required todeliver air in volume sufficient to effect proper combustion, the air passage within the casing on the suction side of the fan being substantially unrestricted, and on the discharge side of the fan the air passages have such proportions and relative positions that the air is not to substantial degree restricted in its flow, and attains only such velocities as are desirable ized oil, and the air velocities do not attain those magnitudes characteristic of the prior art in which. the velocity of the air is of high magnitude to effect or assist in effecting atomization of the oil. In the use of our device high air pressure is not required, and thepressure set up within the casing by means of the fan or blower 18 is only that incidental to the development of a flow of air in proper quantity for sustaining substantially perfect combustion.

Gauges 13 and 44 may be mounted upon the burner casing. 12 and the fuel pipe, re-

spcctively', to afford information for readily maintaining proper relative proportions as between the amount of fuel supplied through the atomizer and the volume of air supplied by the fan. Thus if the fuel gauge shows that the fuel is fed at an increased pressure the speed of the fan may be increased until the air pressure within the casing 12-and hence its amountis increased to a suitable degree.

Our apparatus may be employed as an independent unit or may be one of a series of units applied to either related or unrelated lire doors, and a single controlling device may be employed for controlling supply of power to all of them, and a single valve may be employed for controlling supply of fuel under pressure to the atomizers.

Furthermore, the device may be used in a closed fire room, under pressure in which event the air is forced through the casing 12, and as has been found inpractice, the fan is rotated by the current of air, which is then delivered by the correcting vanes l0 through the fire door with the proper amount of whirl.

By means of adjustability of the fuel pipe 22 and the diffuser 35, the diffusion of flame with respect to the fire box may be readily adjusted to secure as wide flame diffusion as possible without interference between such flame and the walls of the firebox door. Referring now moreparticularly to Figs. 9 and 10, we have provided a casing 12, a fan 18, a turbine casing 13 and a turbine 16 of substantially the form shown in Figs. 1 to 4. lln this form of device correcting vanes 41 are secured to the casing at a point nearer to the fan than in the form shown in Fig. 1, for assisting a series of vanes tl that are also mounted within the casing 12 to give the proper control to the air that is driven past the atomizer23.

In this form of our apparatus only the fuel pipe 22 is shown adjustable to secure the proper positioning of the diffused flame with respect to the entrance to the furnace. The fan 18 in this form of device functions in the same manner as in the device of Fig. 1.

lhe fuel pipe 22 is supported from the end plate 19 of the turbine casing and by a bear ng 22 which is supported by bolts 22 secured to, the casing 12. This permits of clearance between the fuel pipe 22 and the hollow turbine shaft 17, thus avoiding friction between the fuel pipe and the rotating shaft 17.

Vanes 11, at points adjacent to the atomizer 23, impart a relatively high velocity to the swirling stream of air, which velocity diminishes proportionately as the radial distance from the atomizer increases. The diffuser members 35 and ll do not materially throttle or obstruct the flow of air, but as stated, are for the purpose of giving it the desired angle of movement.

While we do not wish to limit ourselves to the range of air pressures set up by the fan within the casing 12, good results have been obtained by air pressures from one-eighth of lln utilizing light oils of low'viscosity,

such as kerosene and distillates, good results have been obtained by us in supplying the oil at pressures from about 50 pounds per square inch (gauge) up to 300 or 400 pounds per square inch (gauge), the upper limit of pressure depending only upon the type of the atomizer and the strength of the oil service apparatus.

With fuel oils of the higher grades, we have obtained satisfactory results by sup plying the oil at pressures from 100 pounds per square inch up to 300 or 100 pounds per square inch. An operating range from 150 pounds to 250 pounds per square inch is satisfactory under usual conditions.

In employing fuel oils of high viscosity, a pressure range of 150 pounds to 300 or 4-00 pounds per square inch gives good f esults, a good operating pressure under ordinary conditlons being from 175 to 275 pounds per square inch.

Viith burners of sizes to fit larger or smaller furnace openings, the amount of fuel that may be burned will be closely proportional to the areas of the furnace openings.

By pressure atomizer is meant an atomizer in which oil is forced under pressure through a stationary orifice and is atomized upon leaving the orifice.

For a burner designed to fit a ten and onehalf inch furnace opening, the range of capacity within which oil may be satisfactorily burned is from 200 to 850 pounds of oil per hour.

l Vhat we claim is:

1. A liquid fuel burner comprising a casing, a fuel atomizer disposed within the casing and adjacent to the forward end thereof, a fan disposed within the casing and adjacent to the rear of said atomizer, angularly disposed vanes-mounted in front of the fan for giving a desired angularity of mot ement to the air currents that are set up upon rotation of said fan, and other vanes for dividing a portion of said air current into separate concentric currents.

2. A liquid fuel burner comprising a casing, a fuel atomizer disposed within the easing and adjacent to the forward end thereof, a fan disposed within the casing and adjacent to the rear of said atomizer, angularly disposed vanes mounted in front of the fan for giving a desired degree of angular movement to the air currents that are set up upon rotation of said fan, and other vanes disposed between said first named vanes and the atomizer, for dividing a portion of said air currents into concentric currents,

3. A liquid fuel burner which comprises a casing, a mechanical atomizer located in and adjacent to the forward end of said casing, a fan disposed within the casing and adjacent to the rear of said atomizer, means for supplying fuel under pressure to said atomizer, and means for imparting movement to said fan to set up a current of air in a forward direction, the fan and the narrowest portion of the casing to the front of said fan having substantially equal diameters.

4. A liquid fuel burner which comprises a casing, a mechanical atomizer stationary during the normal operation thereof and located adjacent to the forward end of said casing, a fan disposed within the casing and adjacent the rear of said atomizer, means for supplying fuel under pressure to said atomizer, means for imparting movement to said fan to set up a rotating current of air in a forward direction, and means in front of the fan for maintaining a substantially uniform rotative movement of a part of said air for varying speeds of said fan.

5. A burner comprising in combination, a casing, a fluid pressure atomizer within the casing, a blower within said casing to create a flow of air through said casing and a defiector having coaxial passages surrounding said atomizer and arranged to direct the air from said blower in paths which do not intersect the axis of the spray from said atomizer, said deflector passages being free of air deflecting devices, and vanes disposed about the periphery of the outermost coaxial passage for giving an axially rotative motion to a part of the air flowing past said vanes. V i

6. A burner comprising in combination, a casing, an atomizer disposed within the casing, means for supplying fuel to said atomizer, means for directing a flow of air through said casing, and a deflector having co-axial passages surrounding said atomizer, the said passages being inclined outwardly toward their forward ends.

7. A burner comprising in combination, a casing, an atomizer disposed within the easing, means for supplying fuel to said atomizer, means for directing a flow of air through said casing, and a deflector having co-axial passages surrounding said atomizer, said passages diverging from the axis of the spray from said atomizer at successively decreasing angles from the innermost passage to the outermost passage. v

8. A burner comprising in combination, a casing, an atomizer disposed within the easing, means for supplying fuel to said atom izer,, means for directing a flow of air through said casing, and a deflector having co-axial passages surrounding said atomizer, the forward ends of said passages being inclined outwardly, the degree of inclination of the outer walls of those passages nearest the common axis of the passages being greater than that of the corresponding Walls of the outer passages.

9. The combination, in a liquid fuel burner, of a casing, a fuel supply pipe disposed within the casing, an atomizer mounted upon the front endof the fuel pipe, a fan disposed within the casing and adjacent to the rear of said atomizer, and air deflecting members surrounding the said atomizer and supported by said fuel pipe, the position of the atomizer being changeable with respect to said fan independently of the said deflecting members.

10. The combination, in a liquid fuel burner, of a casing, a fan disposed within said casing, a fuel supply pipe disposed within the casing, an atomizer mounted upon the front end of the fuel pipe, and air defleeting members surrounding said atomizer, the position of the atomizer being changeable with respect to the fan and all of said defleeting members.

11. The combination, in a liquid fuel burner, of a casing, a fuel supply pipe disposed within the casing, an atomizer mounted upon the forward end of the fuel pipe, a fan disposed within the casing and adjacent to the rear of said atomizer, and air deflecting members surrounding the said atomizer and supported by said fuel pipe, the positions of the said air deflectors and the atomizer being independently changeable with respect to said fan.

12. A liquid fuel burner comprising a casin a fuel supply pipe disposed within the casing, an atomizer mounted upon the for-- ward end of said pipe, a tubular member surrounding the said pipe, air deflecting members mounted upon the front end of said tubular member, and a fan disposed within the casing adjacent to said atomizer, the positions of the atomizer and tubular member being relatively changeable longitudinally.

13. A liquid fuel burner comprising a casing, a fuel supply pipe extending into the casing, an atomizer mounted on the forward end of said pipe, a tubular member surrounding said pipe, air deflecting members surrounding said atomizer and supported on said tubular member, and a fan in said casing supported to rotate around the axis of said tubular member and out of contact therewith, the positions of said atomizer and said tubular member being relatively changeable longitudinally while the fan is maintained in fixed relation with said casing.

14. A liquid fuel apparatus comprising, a casing, a fuel supply pipe disposed within the casing, an atomizer located upon the forward end of said fuel pipe and stationary during the normal operation of the device, a fan disposed within the casing and to the rear of said atomizer which will impart a helical movement to the incoming air, a mo operation of said atomizer, the fuel pipe being movable longitudinally of the shaft.

16. A fuel burner comprising a hollow shaft, a blower carried by the shaft, a sleeve extending through the shaft, air diffusing members carried upon the forward end of the sleeve, a fuel pipe extending through said sleeve and provided with an orifice at its forward end, and means for rotating said shaft to cause the blower to set up a fiowof air past said diffusing members and orifice, said sleeve and fuel pipe being independently movable longitudinally of the shaft.

17. The combination in a fuel burner, of a hollow shaft, a blower carried by said shaft, a fuel pipe extending through said shaft, and an atomizer mounted upon said fuel pipe in front of the blower, said atomizer being of a smaller diameter than the interior of said shaft, to permit its withdrawal therethrough.

18. The combination in a fuel burner, of a hollow shaft, a fan carried by said shaft, a fuel pipe extending through said shaft, and an atomizer mounted upon said fuel pipe in front of the fan, said atomizer having a diameter substantially the same as the diameter of the fuel pipe, to permit passage thereof through the shaft.

19. lin a system for burning fuel, apparatus for intimately associating liquid fuel with combustion air in a combustion space, comprising a non-rotative pressure atomizer for reducing the fuel to a cone of rapidly moving, finely divided particles, independent of the combustion air, a casing opening into the combustion space, the orifice of said atomizer being. located within said casing, a rotating fan in said. casing at the rear of and adjacent the spray orifice, for producing a whirling column of combustion a1r, and deflectors arranged adjacent to the orifice to direct the column of whirling combustion air from the fan into the cone of divided fuel with the helical motion of the air produced by the fan substantially unchanged.

20. In a system for burning fuel, apparatus for intimately associating liquid fuel with combustion air in a combustion space, comprising a non-rotative pressure atomizerfor reducing the fuel to a, cone of rapidly moving finely divided particles independent by the fan substantially unchanged, and,

vanes on the casing to guide a part only of the whirling combustion air from the fan in its helical path.

21. A fuel burner comprising a casing, a pressure atomizer having its orifice within said casing, a rotating fan for setting up a flow of whirling combustion air and means for directing said whirling air past said atomizer orifice, said fan and directing means being located sufficiently close to the atomizer orifice so, that the air, when it strikes the finely divided fuel issuing from the orifice, is still whirling from the motion given it by the fan.

22. In a system of oil burning, the method of intimately associating the fuel with combustion airvvhich consists in reducing the fuel to a conical spray of rapidly moving, finely divided particles, producing a flow of combustion air in the form of a rapidly whirling, substantially cylindrical column with its axis substantially in alinement with the axis of the spray cone and with the air of each column increasing in density from the center of/the column. outward, projecting the combustion air into the spray cone with the outer denser portions of the air column striking the spray cone at a considerable distance from the apex of the spray cone and the inner, less dense, portions of the column striking the spray cone adjacent the apex of the spray cone.

23. In a system of oil burning, the method of intimately associating the fuel with combustion air which consists in reducing the fuel to a conical spray of rapidly moving, finely divided particles, producing 'a flow of combustion air in the form of a rapidly whirling, substantially cylindrical column with its axis substantially in alinement with the axis of the spray cone and with the air of such column increasing in density from the center of the column outward, project-ing the combustion air into the spray cone with the outer denser portions of the air column striking the spray cone at a considerable distance from the-apex of the spray cone and approximately at right angles to the surface .of the spray cone-and the inner, less dense portions of the column striking the spray cone adjacent the apex of the spray cone,

and burning the mixed fuel and combustion 24:. In a system of oil burning, the method of intimately associating the fuel with combustion air which consists in reducing the fuel to a conical spray of rapidly moving, finely divided particles, producing a flow of combustion air in the form of a rapidly whirling, substantially cylindrical column with its axis substantially in alinement with the axis of the spray cone and with the air of such column increasing in density from the center of the column outward, projecting the combustion air into the spray cone with the outer denser portions of the air column,

striking the spray cone at a considerable distance from the apex of the spray cone and approximately at right angles to the surface of the spray cone and the inner, less dense, portions of the column striking the spray cone adjacent the apex of the spray cone and f in a direction approximately parallel to the axis of the spray cone, and burning the mixed fuel and combustion air.

25. A fuel burner comprising a casing, a conduit, a pressure non-rotatable atomizer in said conduit, a fan for setting up a flow of swirling air past said atomizer, and means to rotate said fan at desired speeds independent of the operation of said atomizer, said fan being located adjacent to the atomizer so that the air when it passes the atomizeris still swirling from the motion given it by the fan. 7

In testimony whereof we have hereunto affixed our signatures this 11th day of Deoember, 1922.

HOMER H. NORTON; ELMER lE. HQBBS. 

